MODE OF TRANSMISSION: In an outbreak, it is hypothesized that the first patient becomes infected as a result of contact with an infected animal (15). Person-to-person transmission occurs via close personal contact with an infected individual or their body fluids during the late stages of infection or after death (1, 2, 15, 27).

Nosocomial infections can occur through contact with infected body fluids due to the reuse of unsterilized syringes, needles, or other medical equipment contaminated with these fluids (1, 2).

Humans may be infected by handling sick or dead non-human primates and are also at risk when handling the bodies of deceased humans in preparation for funerals, suggesting possible transmission through aerosol droplets (2, 6, 28).

In the laboratory, infection through small-particle aerosols has been demonstrated in primates, and airborne spread among humans is strongly suspected, although it has not yet been conclusively demonstrated (1, 6, 13). The importance of this route of transmission is not clear. Poor hygienic conditions can aid the spread of the virus (6).

INCUBATION PERIOD: Two to 21 days, more often 4 – 9 days (1, 13, 14).

COMMUNICABILITY: Communicable as long as blood, secretions, organs, or semen contain the virus. Ebola virus has been isolated from semen 61 days after the onset of illness, and transmission through semen has occurred 7 weeks after clinical recovery (1, 2).

SECTION III - DISSEMINATION

RESERVOIR:

The natural reservoir of Ebola is unknown (1, 2). Antibodies to the virus have been found in the serum of domestic guinea pigs, with no relation to human transmission (29). The virus can be replicated in some bat species native to the area where the virus is found, thus certain bat species may prove to be the natural hosts (26).

SURVIVAL OUTSIDE HOST: The virus can survive in liquid or dried material for a number of days (23). Infectivity is found to be stable at room temperature or at 4°C for several days, and indefinitely stable at -70°C (6, 20). Infectivity can be preserved by lyophilisation.

MODE OF TRANSMISSION: In an outbreak, it is hypothesized that the first patient becomes infected as a result of contact with an infected animal (15). Person-to-person transmission occurs via close personal contact with an infected individual or their body fluids during the late stages of infection or after death (1, 2, 15, 27).

Nosocomial infections can occur through contact with infected body fluids due to the reuse of unsterilized syringes, needles, or other medical equipment contaminated with these fluids (1, 2).

Humans may be infected by handling sick or dead non-human primates and are also at risk when handling the bodies of deceased humans in preparation for funerals, suggesting possible transmission through aerosol droplets (2, 6, 28).

In the laboratory, infection through small-particle aerosols has been demonstrated in primates, and airborne spread among humans is strongly suspected, although it has not yet been conclusively demonstrated (1, 6, 13). The importance of this route of transmission is not clear. Poor hygienic conditions can aid the spread of the virus (6).

INCUBATION PERIOD: Two to 21 days, more often 4 – 9 days (1, 13, 14).

COMMUNICABILITY: Communicable as long as blood, secretions, organs, or semen contain the virus. Ebola virus has been isolated from semen 61 days after the onset of illness, and transmission through semen has occurred 7 weeks after clinical recovery (1, 2).

SECTION III - DISSEMINATION

RESERVOIR:

The natural reservoir of Ebola is unknown (1, 2). Antibodies to the virus have been found in the serum of domestic guinea pigs, with no relation to human transmission (29). The virus can be replicated in some bat species native to the area where the virus is found, thus certain bat species may prove to be the natural hosts (26).

SURVIVAL OUTSIDE HOST: The virus can survive in liquid or dried material for a number of days (23). Infectivity is found to be stable at room temperature or at 4°C for several days, and indefinitely stable at -70°C (6, 20). Infectivity can be preserved by lyophilisation.